BACKGROUND
1. Field
[0001] The present disclosure relates to cooling systems, more specifically to aircraft
electronics thermal regulation systems.
2. Description of Related Art
[0002] High power motor controllers and power conversion devices are either cooled by air
flow or liquid cooling. Liquid is cooled by a ram air heat exchanger. A ram fan is
used for heat rejection on ground. Existing ram air fans can have poor reliability
due to foreign object damage and insufficient motor cooling issues. In next generation
aircraft, however, electronics based power conversion, e.g., to produce variable speed
constant frequency (VSCF) electric power, will increase cooling demand. Cooling such
electronics can be insufficient with existing air cooling or traditional ram air fan
cooling.
[0003] Such conventional methods and systems have generally been considered satisfactory
for their intended purpose. However, there is still a need in the art for improved
aircraft electronics thermal regulation systems. The present disclosure provides a
solution for this need.
SUMMARY
[0004] An electronics cooling system for an aircraft can include a heat exchanger comprising
a coolant circuit, an air circuit, and a fuel circuit such that each of the circuits
is in thermal communication with at least one of the other circuits. The coolant circuit
is in thermal communication with one or more aircraft electronics. The air circuit
is fluidly connectable with at least one air source. The fuel circuit is fluidly connectable
with a fuel tank between the fuel tank and an engine of the aircraft and/or fluidly
connectable with a fuel loop that returns to the fuel tank.
[0005] The air circuit and the fuel circuit can be in direct thermal communication with
the coolant circuit within the heat exchanger. The coolant circuit can include a coolant,
e.g., propylene glycol (e.g., Dowfrost™) or any other suitable coolant.
[0006] The at least one air source can include at least one of a cabin exhaust port and/or
a ram air inlet. The air circuit can be fluidly connectable with both a cabin exhaust
port and a ram air inlet.
[0007] The system can include at least one air valve disposed between the at least one air
source and the heat exchanger to selectively permit airflow from the at least one
air source. In certain embodiments, a fan can be disposed between the cabin exhaust
port and the heat exchanger to facilitate airflow from the cabin exhaust port to the
heat exchanger.
[0008] The system can further include fuel valve disposed between the fuel tank and the
heat exchanger to selectively permit fuel flow to the heat exchanger. In certain embodiments,
the system can include a coolant pump disposed between the aircraft electronics and
the heat exchanger.
[0009] In certain embodiments, the coolant circuit in the heat exchanger can include a plate
shaped portion. The fuel circuit in the heat exchanger can include a plate shaped
portion. The air circuit in the heat exchanger can include fins.
[0010] A method for cooling electronics on an aircraft includes controlling at least one
air valve disposed between at least one air source and a heat exchanger to be closed
during at least one first condition and to be open during at least one second condition,
and controlling a fuel valve disposed between a fuel tank and the heat exchanger to
be open during the at least one first condition and to be closed during the at least
one second condition. The at least one first condition can include at least one first
flight phase and the at least one second condition includes at least one second flight
phase.
[0011] The at least one first flight phase can include at least one of ground operations,
taxi, take off, and climb. The at least one second flight phase can include at least
one of cruise, descent, approach, and landing.
[0012] Controlling the at least one air valve can include controlling the at least one air
valve to allow only ram air to flow to the heat exchanger during cruise. Controlling
the at least one air valve can include controlling the at least one air valve to allow
only cabin exhaust air to flow to the heat exchanger during descent and landing.
[0013] In accordance with at least one aspect of this disclosure, an electronics cooling
system for an aircraft includes a heat exchanger comprising a coolant circuit and
a fuel circuit such that each of the circuits is in thermal communication with the
other circuit. The coolant circuit is in thermal communication with one or more aircraft
electronics. The fuel circuit is fluidly connectable with a fuel tank between the
fuel tank and an engine of the aircraft and/or fluidly connectable with a fuel loop
that returns to the fuel tank.
[0014] These and other features of the systems and methods of the subject disclosure will
become more readily apparent to those skilled in the art from the following detailed
description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] So that those skilled in the art to which the subject disclosure appertains will
readily understand how to make and use the devices and methods of the subject disclosure
without undue experimentation, embodiments thereof will be described in detail herein
below with reference to certain figures, wherein:
Fig. 1 is a schematic view of an embodiments of a system in accordance with this disclosure;
and
Fig. 2 is a side view of an embodiment of a heat exchanger in accordance with this
disclosure.
DETAILED DESCRIPTION
[0016] Reference will now be made to the drawings wherein like reference numerals identify
similar structural features or aspects of the subject disclosure. For purposes of
explanation and illustration, and not limitation, an illustrative view of an embodiment
of a system in accordance with the disclosure is shown in Fig. 1 and is designated
generally by reference character 100. Other embodiments and/or aspects of this disclosure
are shown in Fig. 2. The systems and methods described herein can be used to cool
aircraft electronics.
[0017] Referring to Fig. 1, an electronics cooling system 100 for an aircraft can include
a heat exchanger 101 having a coolant circuit 103, an air circuit 105, and a fuel
circuit 107 such that each of the circuits 103, 105, 107 is in thermal communication
with at least one of the other circuits 103, 105, 107. The coolant circuit 103 is
in thermal communication with one or more aircraft electronics 109, e.g., variable
speed constant frequency electronics (VSCF).
[0018] The coolant circuit 103 can include a coolant, e.g., propylene glycol (such as Dowfrost™)
or any other suitable coolant. In certain embodiments, the system 100 can include
a coolant pump 104 disposed between the aircraft electronics 109 and the heat exchanger
101. The pump 104 can include any suitable pump and/or components thereof (e.g., a
motor, a controller). The aircraft electronics 109 and/or the pump 104 can be housed
in a pressurized portion of the aircraft, however, any suitable location is contemplated
herein.
[0019] The air circuit 105 is fluidly connectable with at least one air source. The at least
one air source can include at least one of a cabin exhaust port 115 and/or a ram air
inlet 117, for example. In certain embodiments, the air circuit 105 can be fluidly
connectable with both a cabin exhaust port 115 and a ram air inlet 117.
[0020] The system 100 can include at least one air valve 119 disposed between the at least
one air source and the heat exchanger 101 to selectively permit airflow from the at
least one air source. In certain embodiments, as shown in Fig. 1, the air valve 119
can be fluidly connectable with both the cabin exhaust port 115 and the ram air inlet
117. The air valve 119 can be a selector valve configured to select between the cabin
exhaust port 115 and the ram air inlet 117 and/or can be configured to allow and/or
shut off airflow from one or both of the cabin exhaust port 115 or the ram air inlet
117.
[0021] In certain embodiments, a fan 121 can be disposed between the cabin exhaust port
115 and the heat exchanger 101 to facilitate airflow from the cabin exhaust port 115
to the heat exchanger 101. The fan 121 can include any suitable fan and/or components
thereof (e.g., a motor, a controller).
[0022] The fuel circuit 107 can be fluidly connectable with a fuel tank 111 between the
fuel tank 111 and an engine 113 of the aircraft. It is also contemplated that the
fuel circuit 107 can be additionally or alternatively fluidly connectable with a fuel
loop 155 that loops fuel back to the fuel tank 111.
[0023] The air circuit 105 and the fuel circuit 107 can be in direct thermal communication
with the coolant circuit 103 within the heat exchanger 101. Any other suitable arrangement
(e.g., indirect communication) is contemplated herein. The system 100 can further
include fuel valve 123 disposed between the fuel tank 111 and the heat exchanger 101
(e.g., downstream of a fuel pump 125) to selectively permit fuel flow to the heat
exchanger 101.
[0024] In certain embodiments, referring additionally to Fig. 2, a heat exchanger 201 can
include any suitable design. For example, as shown, the coolant circuit 203 in the
heat exchanger 201 can include a plate shaped portion 203a. In certain embodiments,
the fuel circuit 207 in the heat exchanger 201 can include a plate shaped portion
207a. The air circuit 205 in the heat exchanger 201 can include fins 205a. The heat
exchanger 201 and portions thereof can be made of any suitable material (e.g., metal).
The cooling plate portion 203a may have a top plate, a bottom plate, and fins (not
shown) therebetween and inside to enhance transfer of heat between coolant and the
external air or fuel flow. The cooling plate portion 207a may have a top plate, a
bottom plate, and fins (not shown) inside to enhance transfer of heat between coolant
and fuel flow.
[0025] The system 100 can further include a controller 127 operatively connected to each
of the valves 119, 123, and/or pumps 104, 121, 125. In certain embodiments, the controller
127 can be configured to operate each of the valves 119, 123 and/or pumps 104, 125,
and/or fan 121 to modify which circuits 103, 105, 107 are used for heat exchange (e.g.,
cooling), for example. The controller 127 can include any suitable hardware and/or
software configured to control one or more of the valves 119, 123 and/or pumps 104,
125, and/or fan 121. The controller 127 can be configured to execute any suitable
embodiment of a method (e.g., as described below) for cooling electronics.
[0026] In certain embodiments, a method for cooling electronics on an aircraft includes
controlling at least one air valve 119 disposed between at least one air source and
a heat exchanger 101 to be closed during at least one first condition and to be open
during at least one second condition. The method also includes controlling a fuel
valve 123 disposed between a fuel tank 111 and the heat exchanger 101 to be open during
at least one first condition and to be closed during at least one second condition,
for example. The at least one first condition can include at least one first flight
phase and the at least one second condition includes at least one second flight phase
[0027] In certain embodiments, the at least one first flight phase can include at least
one of ground operations, taxi, take off, and climb. The at least one second flight
phase can include at least one of cruise, descent, approach, and landing.
[0028] In certain embodiments, controlling the at least one air valve 119 can include controlling
the at least one air valve 119 to allow only ram air to flow to the heat exchanger
101 during cruise. Controlling the at least one air valve 119 can include controlling
the at least one air valve 119 to allow only cabin exhaust air to flow to the heat
exchanger 101 during descent and landing, for example.
[0029] Embodiments allow thermal regulation (e.g., cooling or heating) of electronics. For
example, VSCF cold plates can be cooled by flowing coolant (e.g., Dowfrost™) or any
other suitable coolant through cold pates. Coolant can be pumped to a coolant/fuel/air
heat exchanger 101. This heat exchanger 101 can cool the coolant with either fuel
or air or both. While on ground or take off, the heat exchanger 101 can be cooled
by fuel, for example. For cruise mode, the fuel flow to the heat exchanger 101 can
be stopped, the ram air door can be opened and an air selector/on-off air valve 119
can allow ram air to flow through heat exchanger 101 to cool the coolant. Before landing,
the ram air door can be closed and passenger cabin exhaust air can be used. In this
manner, embodiments allow the elimination of the ram air fan system. Benefits include
a higher reliability of the cooling system and a reduced cost of cooling system. While
systems herein can be used for cooling, it is contemplated that embodiments can be
used for heating and/or any suitable temperature regulation.
[0030] The methods and systems of the present disclosure, as described above and shown in
the drawings, provide for aircraft electronics thermal regulation systems with superior
properties. While the apparatus and methods of the subject disclosure have been shown
and described with reference to embodiments, those skilled in the art will readily
appreciate that changes and/or modifications may be made thereto without departing
from the spirit and scope of the subject disclosure.
1. An electronics cooling system (100) for an aircraft, comprising:
a heat exchanger (101) comprising a coolant circuit, an air circuit (105), and a fuel
circuit (107, 207) such that each of the circuits is in thermal communication with
at least one of the other circuits,
wherein the coolant circuit (203) is in thermal communication with one or more aircraft
electronics,
wherein the air circuit (105) is fluidly connectable with at least one air source,
wherein the fuel circuit (107, 207) is fluidly connectable with a fuel tank (111)
between the fuel tank (111) and an engine of the aircraft and/or fluidly connectable
with a fuel loop that returns to the fuel tank (111).
2. The system of claim 1, wherein the air circuit and the fuel circuit (107) are in direct
thermal communication with the coolant circuit (203) within the heat exchanger (101).
3. The system of claim 1 or 2, wherein the coolant circuit (203) includes a coolant,
and preferably wherein the coolant includes propylene glycol.
4. The system of claim 1, 2 or 3, wherein the at least one air source includes at least
one of a cabin exhaust port (115) and/or a ram air inlet (117).
5. The system of claim 4, wherein the air circuit is fluidly connectable with both a
cabin exhaust port (115) and a ram air inlet (117).
6. The system of claim 4, further comprising at least one air valve (119) disposed between
the at least one air source and the heat exchanger to selectively permit airflow from
the at least one air source.
7. The system of any preceding claim, further comprising a fan disposed between the cabin
exhaust port and the heat exchanger to facilitate airflow from the cabin exhaust port
to the heat exchanger, or further comprising a fuel valve disposed between the fuel
tank and the heat exchanger to selectively permit fuel flow to the heat exchanger.
8. The system of any preceding claim, further comprising a coolant pump disposed between
the aircraft electronics and the heat exchanger, and/or wherein the air circuit (105)
in the heat exchanger (101) includes fins (205a).
9. The system of any preceding claim, wherein the coolant circuit in the heat exchanger
(101) includes a plate shaped portion, and/or wherein the fuel circuit (107, 307)
in the heat exchanger (101) includes a plate shaped portion (207a).
10. A method for cooling electronics on an aircraft, comprising:
controlling at least one air valve (119) disposed between at least one air source
and a heat exchanger (101) to be closed during at least one first condition and to
be open during at least one second condition; and
controlling a fuel valve (123) disposed between a fuel tank and the heat exchanger
to be open during the at least one first condition and to be closed during the at
least one second condition.
11. The method of claim 10, wherein the at least one first condition includes at least
one first flight phase and the at least one second condition includes at least one
second flight phase.
12. The method of claim 11, wherein the at least one first flight phase includes at least
one of ground operations, taxi, take off, and climb.
13. The method of claim 12, wherein the at least one second flight phase includes at least
one of cruise, descent, approach, and landing.
14. The method of claim 13, wherein controlling the at least one air valve (119) includes
controlling the at least one air valve (119) to allow only ram air to flow to the
heat exchanger (101) during cruise, or wherein controlling the at least one air valve
(119) includes controlling the at least one air valve (119) to allow only cabin exhaust
air to flow to the heat exchanger (101) during descent and landing.
15. An electronics cooling system for an aircraft, comprising:
a heat exchanger (141) comprising a coolant circuit (203) and a fuel circuit (107,
207) such that each of the circuits is in thermal communication with the other circuit,
wherein the coolant circuit (203) is in thermal communication with one or more aircraft
electronics,
wherein the fuel circuit (107, 207) is fluidly connectable with a fuel tank (111)
between the fuel tank (111) and an engine of the aircraft and/or fluidly connectable
with a fuel tank loop that returns to the fuel tank (111).